nanog mailing list archives

Re: 204.17.16.0/20 Unreachable via Comcast ASN 7992; Looking for Help or Contacts


From: Phil Fagan <philfagan () gmail com>
Date: Fri, 9 Aug 2013 12:42:46 -0600

Interesting; instability due to reaching this table limit? Good info!


On Thu, Aug 8, 2013 at 10:39 AM, Tony Tauber <ttauber () 1-4-5 net> wrote:

It's a fair question and had nothing to do with the other network (TW
Telecom, in this case, not TIme Warner Cable).
Sorry for not filling in details sooner.

We recently needed to adjust the scale profile on some of our Cisco ASR9k
trident chip (80gig) Line Cards as we reached . The default profile only
supports up to 512k routes and will notify that CEF has run out of
DATA_TYPE_TABLE_SET space as a result. The profile change required (profile
13) requires a reload of the chassis. please be advised.  You might want to
review with your local support team.

The symptom involved BGP neighbor instability and unreachability of some
destinations.
Shutting down that particular BGP session was a temporary work-around
until the adjustment could be made during a demand maintenance window to
minimize disruption.

Thanks,
Tony


On Wed, Aug 7, 2013 at 5:31 PM, Phil Fagan <philfagan () gmail com> wrote:

BGP Noob question here; but wouldn't Time Warner not recieve a prefix if
it
wasn't reachable? Is this an artifact?


On Mon, Aug 5, 2013 at 11:32 AM, Chad Reid <Chad.Reid () apollogrp edu>
wrote:

Thanks for the assistance everyone. This issue was resolved by shutting
down a BGP peering session between Time Warner and Comcast. --Chad

Chad M. Reid, Network Administrator II
Work Hours: Sun. - Tue. 6AM-6PM and  Wed. 6AM-3PM (MST -7)
Apollo Group | IT Services │ IT Operations Center (ITOC)
4025 S. Riverpoint Parkway │ MS: AA-M002 │ Phoenix, AZ 85040
phone: 602.557.6746 │ fax: 602.557.6606 │ email:
chad.reid () apollogrp edu


-----Original Message-----
From: Chad Reid
Sent: Sunday, August 04, 2013 7:41 AM
To: 'nanog () nanog org'
Subject: 204.17.16.0/20 Unreachable via Comcast ASN 7992; Looking for
Help or Contacts

Hello NANOG,

A few hundred of our users that use Comcast in the South East United
States (other regions aren't affected) are unable to access our
websites in
the IP block 204.17.16.0/20. Based upon testing with the users, they're
getting a destination unreachable from a Comcast backbone router in ASN
7922:
be-16-pe03.56marietta.ga.ibone.comcast.net [68.86.83.134] reports:
Destination net unreachable.

We're not a customer of Comcast, nor are any of our ISPs. Because of
this,
we can't find anyone at Comcast to look at this issue nor do we have
good
contact info to even reach someone. Our users in the South East can open
tickets with Comcast technical support, but you can imagine how
successful
they are trying to explain this to frontline support and getting
frontline
support to understand.

Is anyone from Comcast on the list that can assist or know of a contact?


Chad M. Reid, Network Administrator II
Work Hours: Sun. - Tue. 6AM-6PM and  Wed. 6AM-3PM (MST -7) Apollo Group
|
IT Services │ IT Operations Center (ITOC)
4025 S. Riverpoint Parkway │ MS: AA-M002 │ Phoenix, AZ 85040
phone: 602.557.6746 │ fax: 602.557.6606 │ email:
chad.reid () apollogrp edu



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--
Phil Fagan
Denver, CO
970-480-7618





-- 
Phil Fagan
Denver, CO
970-480-7618


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